/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
    * with the License.  You may obtain a copy of the License at
    *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  package org.apache.myfaces.application;
  
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.Comparator;
  import java.util.EnumSet;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.logging.Level;
  import java.util.logging.Logger;
  
  import java.util.regex.Pattern;
  import javax.el.MethodExpression;
  import javax.faces.FacesException;
  import javax.faces.application.ConfigurableNavigationHandler;
  import javax.faces.application.FacesMessage;
  import javax.faces.application.NavigationCase;
  import javax.faces.application.ProjectStage;
  import javax.faces.application.ViewHandler;
  import javax.faces.component.UIComponent;
  import javax.faces.component.UIViewAction;
  import javax.faces.component.UIViewRoot;
  import javax.faces.component.visit.VisitCallback;
  import javax.faces.component.visit.VisitContext;
  import javax.faces.component.visit.VisitHint;
  import javax.faces.component.visit.VisitResult;
  import javax.faces.context.ExternalContext;
  import javax.faces.context.FacesContext;
  import javax.faces.context.PartialViewContext;
  import javax.faces.flow.Flow;
  import javax.faces.flow.FlowCallNode;
  import javax.faces.flow.FlowHandler;
  import javax.faces.flow.FlowNode;
  import javax.faces.flow.MethodCallNode;
  import javax.faces.flow.Parameter;
  import javax.faces.flow.ReturnNode;
  import javax.faces.flow.SwitchCase;
  import javax.faces.flow.SwitchNode;
  import javax.faces.flow.ViewNode;
  import javax.faces.view.ViewDeclarationLanguage;
  import javax.faces.view.ViewMetadata;
  
  import org.apache.myfaces.config.RuntimeConfig;
  import org.apache.myfaces.config.element.NavigationRule;
  import org.apache.myfaces.flow.FlowHandlerImpl;
  import org.apache.myfaces.shared.application.NavigationUtils;
  import org.apache.myfaces.shared.renderkit.html.util.SharedStringBuilder;
  import org.apache.myfaces.shared.util.ClassUtils;
  import org.apache.myfaces.shared.util.HashMapUtils;
  import org.apache.myfaces.shared.util.StringUtils;
  import org.apache.myfaces.util.FilenameUtils;
  import org.apache.myfaces.view.facelets.ViewPoolProcessor;
  import org.apache.myfaces.view.facelets.tag.jsf.PreDisposeViewEvent;
  
  /**
   * @author Thomas Spiegl (latest modification by $Author$)
   * @author Anton Koinov
   * @version $Revision$ $Date$
   */
  public class NavigationHandlerImpl
      extends ConfigurableNavigationHandler
  {
      //private static final Log log = LogFactory.getLog(NavigationHandlerImpl.class);
      private static final Logger log = Logger.getLogger(NavigationHandlerImpl.class.getName());
  
      private static final String SKIP_ITERATION_HINT = "javax.faces.visit.SKIP_ITERATION";
      
      private static final Set<VisitHint> VISIT_HINTS = Collections.unmodifiableSet(
              EnumSet.of(VisitHint.SKIP_ITERATION));    
      
      private static final String OUTCOME_NAVIGATION_SB = "oam.navigation.OUTCOME_NAVIGATION_SB";
      
      private static final Pattern AMP_PATTERN = Pattern.compile("&(amp;)?"); // "&" or "&amp;"
      
      private static final String ASTERISK = "*";
 
     private Map<String, Set<NavigationCase>> _navigationCases = null;
     //private List<String> _wildcardKeys = new ArrayList<String>();
     private List<_WildcardPattern> _wildcardPatterns = new ArrayList<_WildcardPattern>();
     private Boolean _developmentStage;
     
     private Map<String, _FlowNavigationStructure> _flowNavigationStructureMap = 
         new ConcurrentHashMap<String, _FlowNavigationStructure>();
     
     private NavigationHandlerSupport navigationHandlerSupport;
 
     public NavigationHandlerImpl()
     {
         if (log.isLoggable(Level.FINEST))
         {
             log.finest("New NavigationHandler instance created");
         }
     }
 
     @Override
     public void handleNavigation(FacesContext facesContext, String fromAction, String outcome)
     {
         handleNavigation(facesContext, fromAction, outcome, null);
     }
 
     @Override
     public void handleNavigation(FacesContext facesContext, String fromAction, 
         String outcome, String toFlowDocumentId)
     {
         //NavigationCase navigationCase = getNavigationCase(facesContext, fromAction, outcome);
         NavigationContext navigationContext = new NavigationContext();
         NavigationCase navigationCase = null;
         try
         {
             navigationCase = getNavigationCommand(facesContext, navigationContext, fromAction, outcome,
                 toFlowDocumentId);
         }
         finally
         {
             navigationContext.finish(facesContext);
         }
 
         if (navigationCase != null)
         {
             if (log.isLoggable(Level.FINEST))
             {
                 log.finest("handleNavigation fromAction=" + fromAction + " outcome=" + outcome +
                           " toViewId =" + navigationCase.getToViewId(facesContext) +
                           " redirect=" + navigationCase.isRedirect());
             }
             boolean isViewActionProcessingBroadcastAndRequiresRedirect = false;
             if (UIViewAction.isProcessingBroadcast(facesContext))
             {
                 // f:viewAction tag always triggers a redirect to enforce execution of 
                 // the lifecycle again. Note this requires enables flash scope 
                 // keepMessages automatically, because a view action can add messages
                 // and these ones requires to be renderer afterwards.
                 facesContext.getExternalContext().getFlash().setKeepMessages(true);
                 String fromViewId = (facesContext.getViewRoot() == null) ? null :
                     facesContext.getViewRoot().getViewId();
                 String toViewId = navigationCase.getToViewId(facesContext);
                 // A redirect is required only if the viewId changes. If the viewId
                 // does not change, section 7.4.2 says that a redirect/restart JSF
                 // lifecycle is not necessary.
                 if (fromViewId == null && toViewId != null)
                 {
                     isViewActionProcessingBroadcastAndRequiresRedirect = true;
                 }
                 else if (fromViewId != null && !fromViewId.equals(toViewId))
                 {
                     isViewActionProcessingBroadcastAndRequiresRedirect = true;
                 }
             }
             if (navigationCase.isRedirect() || isViewActionProcessingBroadcastAndRequiresRedirect)
             { 
                 //&& (!PortletUtil.isPortletRequest(facesContext)))
                 // Spec section 7.4.2 says "redirects not possible" in this case for portlets
                 //But since the introduction of portlet bridge and the 
                 //removal of portlet code in myfaces core 2.0, this condition
                 //no longer applies
                 
                 ExternalContext externalContext = facesContext.getExternalContext();
                 ViewHandler viewHandler = facesContext.getApplication().getViewHandler();
                 String toViewId = navigationCase.getToViewId(facesContext);
                 
                 String redirectPath = viewHandler.getRedirectURL(
                         facesContext, toViewId, 
                         NavigationUtils.getEvaluatedNavigationParameters(facesContext,
                         navigationCase.getParameters()) ,
                         navigationCase.isIncludeViewParams());
                 
                 // The spec doesn't say anything about how to handle redirect but it is
                 // better to apply the transition here where we have already calculated the
                 // route than add the parameters and delegate to 
                 // FlowHandler.clientWindowTransition(facesContext)
                 applyFlowTransition(facesContext, navigationContext);
                 
                 //Clear ViewMap if we are redirecting to other resource
                 UIViewRoot viewRoot = facesContext.getViewRoot(); 
                 if (viewRoot != null && !toViewId.equals(viewRoot.getViewId()))
                 {
                     //call getViewMap(false) to prevent unnecessary map creation
                     Map<String, Object> viewMap = viewRoot.getViewMap(false);
                     if (viewMap != null)
                     {
                         viewMap.clear();
                     }
                 }
                 
                 // JSF 2.0 the javadoc of handleNavigation() says something like this 
                 // "...If the view has changed after an application action, call
                 // PartialViewContext.setRenderAll(true)...". The effect is that ajax requests
                 // are included on navigation.
                 PartialViewContext partialViewContext = facesContext.getPartialViewContext();
                 String viewId = facesContext.getViewRoot() != null ? facesContext.getViewRoot().getViewId() : null;
                 if ( partialViewContext.isPartialRequest() && 
                      !partialViewContext.isRenderAll() && 
                      toViewId != null &&
                      !toViewId.equals(viewId))
                 {
                     partialViewContext.setRenderAll(true);
                 }
 
                 // Dispose view if the view has been marked as disposable by default action listener
                 ViewPoolProcessor processor = ViewPoolProcessor.getInstance(facesContext);
                 if (processor != null && 
                     processor.isViewPoolEnabledForThisView(facesContext, facesContext.getViewRoot()))
                 {
                     processor.disposeView(facesContext, facesContext.getViewRoot());
                 }
                 
                 // JSF 2.0 Spec call Flash.setRedirect(true) to notify Flash scope and take proper actions
                 externalContext.getFlash().setRedirect(true);
                 try
                 {
                     externalContext.redirect(redirectPath);
                     facesContext.responseComplete();
                 }
                 catch (IOException e)
                 {
                     throw new FacesException(e.getMessage(), e);
                 }
             }
             else
             {
                 ViewHandler viewHandler = facesContext.getApplication().getViewHandler();
                 //create new view
                 String newViewId = navigationCase.getToViewId(facesContext);
 
                 // JSF 2.0 the javadoc of handleNavigation() says something like this 
                 // "...If the view has changed after an application action, call
                 // PartialViewContext.setRenderAll(true)...". The effect is that ajax requests
                 // are included on navigation.
                 PartialViewContext partialViewContext = facesContext.getPartialViewContext();
                 String viewId = facesContext.getViewRoot() != null ? facesContext.getViewRoot().getViewId() : null;
                 if ( partialViewContext.isPartialRequest() && 
                      !partialViewContext.isRenderAll() && 
                      newViewId != null &&
                      !newViewId.equals(viewId))
                 {
                     partialViewContext.setRenderAll(true);
                 }
 
                 if (facesContext.getViewRoot() != null &&
                     facesContext.getViewRoot().getAttributes().containsKey("oam.CALL_PRE_DISPOSE_VIEW"))
                 {
                     try
                     {
                         facesContext.getAttributes().put(SKIP_ITERATION_HINT, Boolean.TRUE);
 
                         VisitContext visitContext = VisitContext.createVisitContext(facesContext, null, VISIT_HINTS);
                         facesContext.getViewRoot().visitTree(visitContext,
                                                              new PreDisposeViewCallback());
                     }
                     finally
                     {
                         facesContext.getAttributes().remove(SKIP_ITERATION_HINT);
                     }
                 }
                 
                 applyFlowTransition(facesContext, navigationContext);
 
                 // Dispose view if the view has been marked as disposable by default action listener
                 ViewPoolProcessor processor = ViewPoolProcessor.getInstance(facesContext);
                 if (processor != null && 
                     processor.isViewPoolEnabledForThisView(facesContext, facesContext.getViewRoot()))
                 {
                     processor.disposeView(facesContext, facesContext.getViewRoot());
                 }
                 
                 // create UIViewRoot for new view
                 UIViewRoot viewRoot = null;
                 
                 String derivedViewId = viewHandler.deriveViewId(facesContext, newViewId);
 
                 if (derivedViewId != null)
                 {
                     ViewDeclarationLanguage vdl = viewHandler.getViewDeclarationLanguage(facesContext, derivedViewId);
                     
                     if (vdl != null)
                     {
                         ViewMetadata metadata = vdl.getViewMetadata(facesContext, newViewId);
                         
                         if (metadata != null)
                         {
                             viewRoot = metadata.createMetadataView(facesContext);
                         }
                     }
                 }
                 
                 // viewRoot can be null here, if ...
                 //   - we don't have a ViewDeclarationLanguage (e.g. when using facelets-1.x)
                 //   - there is no view metadata or metadata.createMetadataView() returned null
                 //   - viewHandler.deriveViewId() returned null
                 if (viewRoot == null)
                 {
                     viewRoot = viewHandler.createView(facesContext, newViewId);
                 }
                 
                 facesContext.setViewRoot(viewRoot);
                 facesContext.renderResponse();
             }
         }
         else
         {
             // no navigationcase found, stay on current ViewRoot
             if (log.isLoggable(Level.FINEST))
             {
                 log.finest("handleNavigation fromAction=" + fromAction + " outcome=" + outcome +
                           " no matching navigation-case found, staying on current ViewRoot");
             }
         }
     }
     
     private void applyFlowTransition(FacesContext facesContext, NavigationContext navigationContext)
     {
         //Apply Flow transition if any
         // Is any flow transition on the way?
         if (navigationContext != null &&
             navigationContext.getSourceFlows() != null ||
             (navigationContext.getTargetFlows() != null &&
              !navigationContext.getTargetFlows().isEmpty()))
         {
             FlowHandler flowHandler = facesContext.getApplication().getFlowHandler();
             for (int i = 0; i < navigationContext.getTargetFlows().size(); i++)
             {
                 Flow sourceFlow = navigationContext.getSourceFlows().get(i);
                 Flow targetFlow = navigationContext.getTargetFlows().get(i);
 
                 flowHandler.transition(facesContext, sourceFlow, targetFlow, 
                     navigationContext.getFlowCallNodes().get(i), 
                     navigationContext.getNavigationCase().getToViewId(facesContext));
                 sourceFlow = targetFlow;
             }
         }
     }
 
     /**
     * @return the navigationHandlerSupport
     */
     protected NavigationHandlerSupport getNavigationHandlerSupport()
     {
         if (navigationHandlerSupport == null)
         {
             navigationHandlerSupport = new DefaultNavigationHandlerSupport();
         }
         return navigationHandlerSupport;
     }
 
     public void setNavigationHandlerSupport(NavigationHandlerSupport navigationHandlerSupport)
     {
         this.navigationHandlerSupport = navigationHandlerSupport;
     }
 
     private static class PreDisposeViewCallback implements VisitCallback
     {
 
         public VisitResult visit(VisitContext context, UIComponent target)
         {
             context.getFacesContext().getApplication().publishEvent(context.getFacesContext(),
                                                                     PreDisposeViewEvent.class, target);
             
             return VisitResult.ACCEPT;
         }
     }
 
     /**
      * Returns the navigation case that applies for the given action and outcome
      */
     public NavigationCase getNavigationCase(FacesContext facesContext, String fromAction, String outcome)
     {
         NavigationContext navigationContext = new NavigationContext();
         try
         {
             return getNavigationCommand(facesContext, navigationContext, fromAction, outcome, null);
         }
         finally
         {
             navigationContext.finish(facesContext);
         }
     }
     
     public NavigationCase getNavigationCommandFromGlobalNavigationCases(
         FacesContext facesContext, String viewId, NavigationContext navigationContext, 
         String fromAction, String outcome)
     {
         Map<String, Set<NavigationCase>> casesMap = getNavigationCases();
         NavigationCase navigationCase = null;
         
         Set<? extends NavigationCase> casesSet;
         if (viewId != null)
         {
             casesSet = casesMap.get(viewId);
             if (casesSet != null)
             {
                 // Exact match?
                 navigationCase = calcMatchingNavigationCase(facesContext, casesSet, fromAction, outcome);
             }
         }
 
         if (navigationCase == null)
         {
             // Wildcard match?
             //List<String> sortedWildcardKeys = getSortedWildcardKeys();
             List<_WildcardPattern> wildcardPatterns = getSortedWildcardPatterns();
             
             for (int i = 0; i < wildcardPatterns.size(); i++)
             {
                 _WildcardPattern wildcardPattern = wildcardPatterns.get(i);
                 if (wildcardPattern.match(viewId))
                 {
                     casesSet = casesMap.get(wildcardPattern.getPattern());
                     if (casesSet != null)
                     {
                         navigationCase = calcMatchingNavigationCase(facesContext, casesSet, fromAction, outcome);
                         if (navigationCase != null)
                         {
                             break;
                         }
                     }
                 }
             }
         }
         return navigationCase;
     }
     
     private Flow calculateTargetFlow(FacesContext facesContext, String outcome, 
         FlowHandler flowHandler, List<Flow> activeFlows, String toFlowDocumentId)
     {
         Flow targetFlow = null;
         if (toFlowDocumentId != null)
         {
             targetFlow = flowHandler.getFlow(facesContext, toFlowDocumentId, outcome);
         }
         if (targetFlow == null && !activeFlows.isEmpty())
         {
             for (Flow currentFlow : activeFlows)
             {
                 targetFlow = flowHandler.getFlow(facesContext, currentFlow.getDefiningDocumentId(), outcome);
                 if (targetFlow != null)
                 {
                     break;
                 }
             }
         }
         if (targetFlow == null)
         {
             targetFlow = flowHandler.getFlow(facesContext, "", outcome);
         }
         return targetFlow;
     }
 
     public NavigationCase getNavigationCommand(
         FacesContext facesContext, NavigationContext navigationContext, String fromAction, String outcome, 
         String toFlowDocumentId)
     {
         String viewId = facesContext.getViewRoot() != null ? facesContext.getViewRoot().getViewId() : null;
         NavigationCase navigationCase = getNavigationCommandFromGlobalNavigationCases(
                 facesContext, viewId, navigationContext, fromAction, outcome);
         if (outcome != null && navigationCase == null)
         {
             FlowHandler flowHandler = facesContext.getApplication().getFlowHandler();
             List<Flow> activeFlows = FlowHandlerImpl.getActiveFlows(facesContext, flowHandler);
             // JSF 2.2 section 7.4.2: "... When outside of a flow, view identifier 
             // has the additional possibility of being a flow id.
             Flow targetFlow = calculateTargetFlow(facesContext, outcome, flowHandler, activeFlows, toFlowDocumentId);
             Flow currentFlow = navigationContext.getCurrentFlow(facesContext);
             FlowCallNode targetFlowCallNode = null;
             boolean startFlow = false;
             String startFlowDocumentId = null;
             String startFlowId = null;
             boolean checkFlowNode = false;
             String outcomeToGo = outcome;
             String actionToGo = fromAction;
             
             if (currentFlow != null)
             {
                 // JSF 2.2 section 7.4.2: When inside a flow, a view identifier has 
                 // the additional possibility of being the id of any node within the 
                 // current flow or the id of another flow
                 if (targetFlow != null)
                 {
                     if (flowHandler.isActive(facesContext, targetFlow.getDefiningDocumentId(), targetFlow.getId()))
                     {
                         // If the flow is already active, there is a chance that a node id has the same name as
                         // the flow and if that so, give preference to that node instead reenter into the flow.
                         FlowNode flowNode = targetFlow.getNode(outcome);
                         if (flowNode != null)
                         {
                             checkFlowNode = true;
                         }
                         else
                         {
                             startFlow = true;
                         }
                     }
                     else
                     {
                         startFlow = true;
                     }
                 }
                 else
                 {
                     // Check if thie 
                     checkFlowNode = true;
                 }
             }
             else
             {
                 if (targetFlow != null)
                 {
                     // start flow!
                     startFlow = true;
                 }
             }
             if (!startFlow)
             {
                 for (Flow activeFlow : activeFlows)
                 {
                     FlowNode node = activeFlow.getNode(outcome);
                     if (node != null)
                     {
                         currentFlow = activeFlow;
                         break;
                     }
                     _FlowNavigationStructure flowNavigationStructure = _flowNavigationStructureMap.get(
                             activeFlow.getId());
                     navigationCase = getNavigationCaseFromFlowStructure(facesContext, 
                             flowNavigationStructure, fromAction, outcome, viewId);
                     if (navigationCase != null)
                     {
                         currentFlow = activeFlow;
                         break;
                     }
                 }
             }
             // If is necessary to enter a flow or there is a current
             // flow and it is necessary to check a flow node
             if (startFlow || (checkFlowNode && currentFlow != null))
             {
                 boolean complete = false;
                 boolean checkNavCase = true;
 
                 while (!complete && (startFlow || checkFlowNode))
                 {
                     if (startFlow)
                     {
                         if (flowHandler.isActive(facesContext, targetFlow.getDefiningDocumentId(), targetFlow.getId())
                             && targetFlowCallNode == null)
                         {
                             // Add the transition to exit from the flow
                             Flow baseReturnFlow = navigationContext.getCurrentFlow(facesContext);
                             // This is the part when the pseudo "recursive call" is done. 
                             while (baseReturnFlow != null && !(baseReturnFlow.getDefiningDocumentId().equals(
                                     targetFlow.getDefiningDocumentId()) &&
                                    baseReturnFlow.getId().equals(targetFlow.getId())) )
                             {
                                 navigationContext.popFlow(facesContext);
                                 baseReturnFlow = navigationContext.getCurrentFlow(facesContext);
                             }
                             navigationContext.popFlow(facesContext);
                             currentFlow = navigationContext.getCurrentFlow(facesContext);
                             navigationContext.addTargetFlow(baseReturnFlow, currentFlow, null);
                         }
                         if (startFlowId == null)
                         {
                             startFlowDocumentId = targetFlow.getDefiningDocumentId();
                             startFlowId = targetFlowCallNode == null ? targetFlow.getId() : targetFlowCallNode.getId();
                         }
                         navigationContext.addTargetFlow(currentFlow, targetFlow, targetFlowCallNode);
                         targetFlowCallNode = null;
                         // Since we start a new flow, the current flow is now the
                         // target flow.
                         navigationContext.pushFlow(facesContext, targetFlow);
                         currentFlow = targetFlow;
                         //No outboundCallNode.
                         //Resolve start node.
                         outcomeToGo = resolveStartNodeOutcome(targetFlow);
                         checkFlowNode = true;
                         startFlow = false;
                     }
                     if (checkFlowNode)
                     {
                         FlowNode flowNode = currentFlow.getNode(outcomeToGo);
                         if (flowNode != null)
                         {
                             checkNavCase = true;
                             if (!complete && flowNode instanceof SwitchNode)
                             {
                                 outcomeToGo = calculateSwitchOutcome(facesContext, (SwitchNode) flowNode);
                                 // Start over again checking if the node exists.
                                 //fromAction = currentFlow.getId();
                                 actionToGo = currentFlow.getId();
                                 flowNode = currentFlow.getNode(outcomeToGo);
                                 continue;
                             }
                             if (!complete && flowNode instanceof FlowCallNode)
                             {
                                 // "... If the node is a FlowCallNode, save it aside as facesFlowCallNode. ..."
                                 FlowCallNode flowCallNode = (FlowCallNode) flowNode;
                                 targetFlow = calculateFlowCallTargetFlow(facesContext, 
                                     flowHandler, flowCallNode, currentFlow);
                                 if (targetFlow != null)
                                 {
                                     targetFlowCallNode = flowCallNode;
                                     startFlow = true;
                                     continue;
                                 }
                                 else
                                 {
                                     // Ask the FlowHandler for a Flow for this flowId, flowDocumentId pair. Obtain a 
                                     // reference to the start node and execute this algorithm again, on that start node.
                                     complete = true;
                                 }
                             }
                             if (!complete && flowNode instanceof MethodCallNode)
                             {
                                 MethodCallNode methodCallNode = (MethodCallNode) flowNode;
                                 String vdlViewIdentifier = calculateVdlViewIdentifier(facesContext, methodCallNode);
                                 // note a vdlViewIdentifier could be a flow node too
                                 if (vdlViewIdentifier != null)
                                 {
                                     outcomeToGo = vdlViewIdentifier;
                                     actionToGo = currentFlow.getId();
                                     continue;
                                 }
                                 else
                                 {
                                     complete = true;
                                 }
                             }
                             if (!complete && flowNode instanceof ReturnNode)
                             {
                                 ReturnNode returnNode = (ReturnNode) flowNode;
                                 String fromOutcome = returnNode.getFromOutcome(facesContext);
                                 actionToGo = currentFlow.getId();
                                 Flow sourceFlow = currentFlow;
                                 Flow baseReturnFlow = navigationContext.getCurrentFlow(facesContext);
                                 // This is the part when the pseudo "recursive call" is done. 
                                 while (baseReturnFlow != null && !(baseReturnFlow.getDefiningDocumentId().equals(
                                         currentFlow.getDefiningDocumentId()) &&
                                        baseReturnFlow.getId().equals(currentFlow.getId())) )
                                 {
                                     navigationContext.popFlow(facesContext);
                                     baseReturnFlow = navigationContext.getCurrentFlow(facesContext);
                                 }
                                 navigationContext.popFlow(facesContext);
                                 currentFlow = navigationContext.getCurrentFlow(facesContext);
                                 navigationContext.addTargetFlow(sourceFlow, currentFlow, null);
                                 outcomeToGo = fromOutcome;
                                 String lastDisplayedViewId = navigationContext.getLastDisplayedViewId(facesContext, 
                                             currentFlow);
                                 
                                 // The part where FlowHandler.NULL_FLOW is passed as documentId causes the effect of
                                 // do not take into account the documentId of the returned flow in the command. In 
                                 // theory there is no Flow with defining documentId as FlowHandler.NULL_FLOW. It has 
                                 // sense because the one who specify the return rules should be the current flow 
                                 // after it is returned.
                                 navigationCase = getNavigationCommand(facesContext, 
                                         navigationContext, actionToGo, outcomeToGo, FlowHandler.NULL_FLOW);
                                 if (navigationCase != null)
                                 {
                                     navigationCase = new FlowNavigationCase(navigationCase, 
                                         flowNode.getId(), FlowHandler.NULL_FLOW);
                                     complete = true;
                                 }
                                 else
                                 {
                                     // No navigation case
                                     if (lastDisplayedViewId != null)
                                     {
                                         navigationCase = createNavigationCase(
                                             viewId, flowNode.getId(), lastDisplayedViewId, FlowHandler.NULL_FLOW);
                                         complete = true;
                                     }
                                 }
                                 if (currentFlow == null)
                                 {
                                     complete = true;
                                 }
                                 continue;
                             }
                             if (!complete && flowNode instanceof ViewNode)
                             {
                                 ViewNode viewNode = (ViewNode) flowNode;
                                 navigationCase = createNavigationCase(viewId, flowNode.getId(), 
                                     viewNode.getVdlDocumentId());
                                 complete = true;
                             }
                             else
                             {
                                 //Should not happen
                                 complete = true;
                             }
                         }
                         else if (checkNavCase)
                         {
                             // Not found in current flow.
                             _FlowNavigationStructure flowNavigationStructure = _flowNavigationStructureMap.get(
                                     currentFlow.getId());
                             navigationCase = getNavigationCaseFromFlowStructure(facesContext, 
                                     flowNavigationStructure, actionToGo, outcomeToGo, viewId);
                             
                             // JSF 2.2 section 7.4.2 "... any text that references a view identifier, such as 
                             // <from-view-id> or <to-view-id>,
                             // can also refer to a flow node ..."
                             if (navigationCase != null)
                             {
                                 outcomeToGo = navigationCase.getToViewId(facesContext);
                                 checkNavCase = false;
                             }
                             else
                             {
                                 // No matter if navigationCase is null or not, complete the look.
                                 complete = true;
                             }
                         }
                         else
                         {
                             complete = true;
                         }
                     }
                 }
                 // Apply implicit navigation rules over outcomeToGo
                 if (outcomeToGo != null && navigationCase == null)
                 {
                     navigationCase = getOutcomeNavigationCase (facesContext, actionToGo, outcomeToGo);
                 }
             }
             if (startFlowId != null)
             {
                 navigationCase = new FlowNavigationCase(navigationCase, startFlowId, startFlowDocumentId);
             }
         }
         if (outcome != null && navigationCase == null)
         {
             //if outcome is null, we don't check outcome based nav cases
             //otherwise, if navgiationCase is still null, check outcome-based nav cases
             navigationCase = getOutcomeNavigationCase (facesContext, fromAction, outcome);
         }
         if (outcome != null && navigationCase == null && !facesContext.isProjectStage(ProjectStage.Production))
         {
             final FacesMessage facesMessage = new FacesMessage("No navigation case match for viewId " + viewId + 
                     ",  action " + fromAction + " and outcome " + outcome);
             facesMessage.setSeverity(FacesMessage.SEVERITY_WARN);
             facesContext.addMessage(null, facesMessage);
         }
         if (navigationCase != null)
         {
             navigationContext.setNavigationCase(navigationCase);
         }
         return navigationContext.getNavigationCase();
         // if navigationCase == null, will stay on current view
     }
 
     private String resolveStartNodeOutcome(Flow targetFlow)
     {
         String outcomeToGo;
         if (targetFlow.getStartNodeId() == null)
         {
             // In faces-config javadoc says:
             // "If there is no <start-node> element declared, it 
             //  is assumed to be <flowName>.xhtml."
             outcomeToGo = "/" + targetFlow.getId()+ "/" + 
                 targetFlow.getId() + ".xhtml";
         }
         else
         {
             outcomeToGo = targetFlow.getStartNodeId();
         }
         return outcomeToGo;
     }
     
     private String calculateSwitchOutcome(FacesContext facesContext, SwitchNode switchNode)
     {
         String outcomeToGo = null;
         boolean resolved = false;
         // "... iterate over the NavigationCase instances returned from its getCases()
         // method. For each, one call getCondition(). If the result is true, let vdl 
         // view identifier be the value of its fromOutcome property.
         for (SwitchCase switchCase : switchNode.getCases())
         {
             Boolean isConditionTrue = switchCase.getCondition(facesContext);
             if (Boolean.TRUE.equals(isConditionTrue))
             {
                 outcomeToGo = switchCase.getFromOutcome();
                 resolved = true;
                 break;
             }
         }
         if (!resolved)
         {
             outcomeToGo = switchNode.getDefaultOutcome(facesContext);
         }
         return outcomeToGo;
     }
     
     private Flow calculateFlowCallTargetFlow(FacesContext facesContext, FlowHandler flowHandler,
         FlowCallNode flowCallNode, Flow currentFlow)
     {
         Flow targetFlow = null;
         // " ... Let flowId be the value of its calledFlowId property and flowDocumentId 
         // be the value of its calledFlowDocumentId property. .."
 
         // " ... If no flowDocumentId exists for the node, let it be the string 
         // resulting from flowId + "/" + flowId + ".xhtml". ..." 
         // -=Leonardo Uribe=- flowDocumentId is inconsistent, waiting for answer of the EG,
         // for not let it be null.
 
         String calledFlowDocumentId = flowCallNode.getCalledFlowDocumentId(facesContext);
         if (calledFlowDocumentId == null)
         {
             calledFlowDocumentId = currentFlow.getDefiningDocumentId();
         }
         targetFlow = flowHandler.getFlow(facesContext, 
             calledFlowDocumentId, 
             flowCallNode.getCalledFlowId(facesContext));
         if (targetFlow == null && !"".equals(calledFlowDocumentId))
         {
             targetFlow = flowHandler.getFlow(facesContext, "", 
                 flowCallNode.getCalledFlowId(facesContext));
         }
         return targetFlow;
     }
     
     private String calculateVdlViewIdentifier(FacesContext facesContext, MethodCallNode methodCallNode)
     {
         String vdlViewIdentifier = null;
         MethodExpression method = methodCallNode.getMethodExpression();
         if (method != null)
         {
             Object value = invokeMethodCallNode(facesContext, methodCallNode);
             if (value != null)
             {
                 vdlViewIdentifier = value.toString();
             }
             else if (methodCallNode.getOutcome() != null)
             {
                 vdlViewIdentifier = (String) methodCallNode.getOutcome().getValue(
                     facesContext.getELContext());
             }
         }
         return vdlViewIdentifier;
     }
     
     private Object invokeMethodCallNode(FacesContext facesContext, MethodCallNode methodCallNode)
     {
         MethodExpression method = methodCallNode.getMethodExpression();
         Object value = null;
         
         if (methodCallNode.getParameters() != null &&
             !methodCallNode.getParameters().isEmpty())
         {
             Object[] parameters = new Object[methodCallNode.getParameters().size()];
             Class[] clazzes = new Class[methodCallNode.getParameters().size()];
             for (int i = 0; i < methodCallNode.getParameters().size(); i++)
             {
                 Parameter param = methodCallNode.getParameters().get(i);
                 parameters[i] = param.getValue().getValue(facesContext.getELContext());
                 clazzes[i] = param.getName() != null ? 
                     ClassUtils.simpleJavaTypeToClass(param.getName()) :
                     (parameters[i] == null ? String.class : parameters[i].getClass());
             }
             
             // Now we need to recreate the EL method expression with the correct clazzes as parameters.
             // We should do it per invocation, because we don't know the parameter type.
             method = facesContext.getApplication().getExpressionFactory().createMethodExpression(
                 facesContext.getELContext(), method.getExpressionString(), null, clazzes);
             value = method.invoke(facesContext.getELContext(), parameters);
         }
         else
         {
             value = method.invoke(facesContext.getELContext(), null);
         }
         return value;
     }
     
     private NavigationCase getNavigationCaseFromFlowStructure(FacesContext facesContext, 
             _FlowNavigationStructure flowNavigationStructure, String fromAction, String outcome, String viewId)
     {
         Set<NavigationCase> casesSet = null;
         NavigationCase navigationCase = null;
         
         if (viewId != null)
         {
             casesSet = flowNavigationStructure.getNavigationCases().get(viewId);
             if (casesSet != null)
             {
                 // Exact match?
                 navigationCase = calcMatchingNavigationCase(facesContext, casesSet, fromAction, outcome);
             }
         }
         if (navigationCase == null)
         {
             List<_WildcardPattern> wildcardPatterns = flowNavigationStructure.getWildcardKeys();
             for (int i = 0; i < wildcardPatterns.size(); i++)
             {
                 _WildcardPattern wildcardPattern = wildcardPatterns.get(i);
                 if (wildcardPattern.match(viewId))
                 {
                     casesSet = flowNavigationStructure.getNavigationCases().get(wildcardPattern.getPattern());
                     if (casesSet != null)
                     {
                         navigationCase = calcMatchingNavigationCase(facesContext, casesSet, fromAction, outcome);
                         if (navigationCase != null)
                         {
                             break;
                         }
                     }
                 }
             }
         }
         return navigationCase;
     }
     
     /**
      * Derive a NavigationCase from a flow node. 
      * 
      * @param flowNode
      * @return 
      */
     private NavigationCase createNavigationCase(String fromViewId, String outcome, String toViewId)
     {
         return new NavigationCase(fromViewId, null, outcome, null, toViewId, null, false, false);
     }
     
     private NavigationCase createNavigationCase(String fromViewId, String outcome, 
         String toViewId, String toFlowDocumentId)
     {
         return new NavigationCase(fromViewId, null, outcome, null, toViewId, 
             toFlowDocumentId, null, false, false);
     }
     
     /**
      * Performs the algorithm specified in 7.4.2 for situations where no navigation cases are defined and instead
      * the navigation case is to be determined from the outcome.
      * 
      * TODO: cache results?
      */
     private NavigationCase getOutcomeNavigationCase (FacesContext facesContext, String fromAction, String outcome)
     {
         String implicitViewId = null;
         boolean includeViewParams = false;
         int index;
         boolean isRedirect = false;
         String queryString = null;
         NavigationCase result = null;
         String viewId = facesContext.getViewRoot() != null ? facesContext.getViewRoot().getViewId() : null;
         //String viewIdToTest = outcome;
         StringBuilder viewIdToTest = SharedStringBuilder.get(facesContext, OUTCOME_NAVIGATION_SB);
         viewIdToTest.append(outcome);
         
         // If viewIdToTest contains a query string, remove it and set queryString with that value.
         index = viewIdToTest.indexOf ("?");
         if (index != -1)
         {
             queryString = viewIdToTest.substring (index + 1);
             //viewIdToTest = viewIdToTest.substring (0, index);
             viewIdToTest.setLength(index);
             
             // If queryString contains "faces-redirect=true", set isRedirect to true.
             if (queryString.indexOf ("faces-redirect=true") != -1)
             {
                 isRedirect = true;
             }
             
             // If queryString contains "includeViewParams=true" or 
             // "faces-include-view-params=true", set includeViewParams to true.
             if (queryString.indexOf("includeViewParams=true") != -1 
                     || queryString.indexOf("faces-include-view-params=true") != -1)
             {
                 includeViewParams = true;
             }
         }
         
         // If viewIdToTest does not have a "file extension", use the one from the current viewId.
         index = viewIdToTest.indexOf (".");
         if (index == -1)
         {
             if (viewId != null)
             {
                 index = viewId.lastIndexOf('.');
 
                 if (index != -1)
                 {
                     //viewIdToTest += viewId.substring (index);
                     viewIdToTest.append(viewId.substring (index));
                 }
             }
             else
             {
                 // This case happens when for for example there is a ViewExpiredException,
                 // and a custom ExceptionHandler try to navigate using implicit navigation.
                 // In this case, there is no UIViewRoot set on the FacesContext, so viewId 
                 // is null.
 
                 // In this case, it should try to derive the viewId of the view that was
                 // not able to restore, to get the extension and apply it to
                 // the implicit navigation.
                 String tempViewId = getNavigationHandlerSupport().calculateViewId(facesContext);
                 if (tempViewId != null)
                 {
                     index = tempViewId.lastIndexOf('.');
                     if(index != -1)
                     {
                         viewIdToTest.append(tempViewId.substring (index));
                     }
                 }
             }
             if (log.isLoggable(Level.FINEST))
             {
                 log.finest("getOutcomeNavigationCase -> viewIdToTest: " + viewIdToTest);
             } 
         }
 
         // If viewIdToTest does not start with "/", look for the last "/" in viewId.  If not found, simply prepend "/".
         // Otherwise, prepend everything before and including the last "/" in viewId.
         
         //if (!viewIdToTest.startsWith ("/") && viewId != null)
         boolean startWithSlash = false;
         if (viewIdToTest.length() > 0)
         {
             startWithSlash = (viewIdToTest.charAt(0) == '/');
         } 
         if (!startWithSlash) 
         {
             index = -1;
             if( viewId != null )
             {
                index = viewId.lastIndexOf('/');
             }
             
             if (index == -1)
             {
                 //viewIdToTest = "/" + viewIdToTest;
                 viewIdToTest.insert(0,"/");
             }
             
             else
             {
                 //viewIdToTest = viewId.substring (0, index + 1) + viewIdToTest;
                 viewIdToTest.insert(0, viewId, 0, index + 1);
             }
         }
         
         // Apply normalization 
         String viewIdToTestString = null;
         boolean applyNormalization = false;
         
         for (int i = 0; i < viewIdToTest.length()-1; i++)
         {
             if (viewIdToTest.charAt(i) == '.' &&
                 viewIdToTest.charAt(i+1) == '/')
             {
                 applyNormalization = true; 
                 break;
             }
         }
         if (applyNormalization)
         {
             viewIdToTestString = FilenameUtils.normalize(viewIdToTest.toString(), true);
         }
         else
         {
             viewIdToTestString = viewIdToTest.toString();
         }
         
         // Call ViewHandler.deriveViewId() and set the result as implicitViewId.
         try
         {
             implicitViewId = facesContext.getApplication().getViewHandler().deriveViewId (
                     facesContext, viewIdToTestString);
         }
         
         catch (UnsupportedOperationException e)
         {
             // This is the case when a pre-JSF 2.0 ViewHandler is used.
             // In this case, the default algorithm must be used.
             // FIXME: I think we're always calling the "default" ViewHandler.deriveViewId() algorithm and we don't
             // distinguish between pre-JSF 2.0 and JSF 2.0 ViewHandlers.  This probably needs to be addressed.
         }
         
         if (implicitViewId != null)
         {
             // Append all params from the queryString
             // (excluding faces-redirect, includeViewParams and faces-include-view-params)
             Map<String, List<String>> params = null;
             if (queryString != null && !"".equals(queryString))
             {
                 //String[] splitQueryParams = queryString.split("&(amp;)?"); // "&" or "&amp;"
                 String[] splitQueryParams = AMP_PATTERN.split(queryString); // "&" or "&amp;"
                 params = new HashMap<String, List<String>>(splitQueryParams.length, 
                         (splitQueryParams.length* 4 + 3) / 3);
                 for (String queryParam : splitQueryParams)
                 {
                     String[] splitParam = StringUtils.splitShortString(queryParam, '=');
                     if (splitParam.length == 2)
                     {
                         // valid parameter - add it to params
                         if ("includeViewParams".equals(splitParam[0])
                                 || "faces-include-view-params".equals(splitParam[0])
                                 || "faces-redirect".equals(splitParam[0]))
                         {
                             // ignore includeViewParams, faces-include-view-params and faces-redirect
                             continue;
                         }
                         List<String> paramValues = params.get(splitParam[0]);
                         if (paramValues == null)
                         {
                             // no value for the given parameter yet
                             paramValues = new ArrayList<String>();
                             params.put(splitParam[0], paramValues);
                         }
                         paramValues.add(splitParam[1]);
                     }
                     else
                     {
                         // invalid parameter
                         throw new FacesException("Invalid parameter \"" + 
                                 queryParam + "\" in outcome " + outcome);
                     }
                 }
             }
             
             // Finally, create the NavigationCase.
             result = new NavigationCase (viewId, fromAction, outcome, null, 
                     implicitViewId, params, isRedirect, includeViewParams);
         }
         
         return result;
     }
     
     /**
      * Returns the view ID that would be created for the given action and outcome
      */
     public String getViewId(FacesContext context, String fromAction, String outcome)
     {
         return this.getNavigationCase(context, fromAction, outcome).getToViewId(context);
     }
 
     /**
      * TODO
      * Invoked by the navigation handler before the new view component is created.
      * @param viewId The view ID to be created
      * @return The view ID that should be used instead. If null, the view ID passed
      * in will be used without modification.
      */
     public String beforeNavigation(String viewId)
     {
         return null;
     }
 
     private NavigationCase calcMatchingNavigationCase(FacesContext context,
                                                       Set<? extends NavigationCase> casesList,
                                                       String actionRef,
                                                       String outcome)
     {
         NavigationCase noConditionCase = null;
         NavigationCase firstCase = null;
         NavigationCase firstCaseIf = null;
         NavigationCase secondCase = null;
         NavigationCase secondCaseIf = null;
         NavigationCase thirdCase = null;
         NavigationCase thirdCaseIf = null;
         NavigationCase fourthCase = null;
         NavigationCase fourthCaseIf = null;
                         
         for (NavigationCase caze : casesList)
         {
             String cazeOutcome = caze.getFromOutcome();
             String cazeActionRef = caze.getFromAction();
             Boolean cazeIf = caze.getCondition(context);
             boolean ifMatches = (cazeIf == null ? false : cazeIf.booleanValue());
             // JSF 2.0: support conditional navigation via <if>.
             // Use for later cases.
             
             if(outcome == null && (cazeOutcome != null || cazeIf == null) && actionRef == null)
             {
                 //To match an outcome value of null, the <from-outcome> must be absent and the <if> element present.
                 continue;
             }
             
             //If there are no conditions on navigation case save it and return as last resort
             if (cazeOutcome == null && cazeActionRef == null &&
                 cazeIf == null && noConditionCase == null && outcome != null)
             {
                 noConditionCase = caze;
             }
             
             if (cazeActionRef != null)
             {
                 if (cazeOutcome != null)
                 {
                     if ((actionRef != null) && (outcome != null) && cazeActionRef.equals (actionRef) &&
                             cazeOutcome.equals (outcome))
                     {
                         // First case: match if <from-action> matches action and <from-outcome> matches outcome.
                         // Caveat: evaluate <if> if available.
 
                         if (cazeIf != null)
                         {
                             if (ifMatches)
                             {
                                 firstCaseIf = caze;
                                 //return caze;
                             }
 
                             continue;
                         }
                         else
                         {
                             firstCase = caze;
                             //return caze;
                         }
                     }
                 }
                 else
                 {
                     if ((actionRef != null) && cazeActionRef.equals (actionRef))
                     {
                         // Third case: if only <from-action> specified, match against action.
                         // Caveat: if <if> is available, evaluate.  If not, only match if outcome is not null.
 
                         if (cazeIf != null)
                         {
                             if (ifMatches)
                             {
                                 thirdCaseIf = caze;
                                 //return caze;
                             }
                             
                             continue;
                         }
                         else
                         {
                             if (outcome != null)
                             {
                                 thirdCase = caze;
                                 //return caze;
                             }
                             
                             continue;
                         }
                     }
                     else
                     {
                         // cazeActionRef != null and cazeOutcome == null
                         // but cazeActionRef does not match. No additional operation
                         // required because cazeIf is only taken into account 
                         // it cazeActionRef match. 
                         continue;
                     }
                 }
             }
             else
             {
                 if (cazeOutcome != null && (outcome != null) && cazeOutcome.equals (outcome))
                 {
                     // Second case: if only <from-outcome> specified, match against outcome.
                     // Caveat: if <if> is available, evaluate.
 
                     if (cazeIf != null)
                     {
                         if (ifMatches)
                         {
                             secondCaseIf = caze;
                             //return caze;
                         }
 
                         continue;
                     }
                     else
                     {
                         secondCase = caze;
                         //return caze;
                     }
                 }
             }
 
             // Fourth case: anything else matches if outcome is not null or <if> is specified.
 
             if (outcome != null && cazeIf != null)
             {
                 // Again, if <if> present, evaluate.
                 if (ifMatches)
                 {
                     fourthCaseIf = caze;
                     //return caze;
                 }
 
                 continue;
             }
 
             if ((cazeIf != null) && ifMatches)
             {
                 fourthCase = caze;
                 //return caze;
             }
         }
         
         if (firstCaseIf != null)
         {
             return firstCaseIf;
         }
         else if (firstCase != null)
         {
             return firstCase;
         }
         else if (secondCaseIf != null)
         {
             return secondCaseIf;
         }
         else if (secondCase != null)
         {
             return secondCase;
         }
         else if (thirdCaseIf != null)
         {
             return thirdCaseIf;
         }
         else if (thirdCase != null)
         {
             return thirdCase;
         }
         else if (fourthCaseIf != null)
         {
             return fourthCaseIf;
         }
         else if (fourthCase != null)
         {
             return fourthCase;
         }
         
         return noConditionCase;
     }
 
     private List<_WildcardPattern> getSortedWildcardPatterns()
     {
         return _wildcardPatterns;
     }
 
     @Override
     public Map<String, Set<NavigationCase>> getNavigationCases()
     {
         if (_developmentStage == null)
         {
             _developmentStage = FacesContext.getCurrentInstance().isProjectStage(ProjectStage.Development);
         }
         if (!Boolean.TRUE.equals(_developmentStage))
         {
             if (_navigationCases == null)
             {
                 FacesContext facesContext = FacesContext.getCurrentInstance();
                 ExternalContext externalContext = facesContext.getExternalContext();
                 RuntimeConfig runtimeConfig = RuntimeConfig.getCurrentInstance(externalContext);
                 
                 calculateNavigationCases(runtimeConfig);
             }
             return _navigationCases;
         }
         else
         {
             FacesContext facesContext = FacesContext.getCurrentInstance();
             ExternalContext externalContext = facesContext.getExternalContext();
             RuntimeConfig runtimeConfig = RuntimeConfig.getCurrentInstance(externalContext);
 
             if (_navigationCases == null || runtimeConfig.isNavigationRulesChanged())
             {
                 calculateNavigationCases(runtimeConfig);
             }
             return _navigationCases;
         }
     }
 
     @Override
     public void inspectFlow(FacesContext context, Flow flow)
     {
         Map<String, Set<NavigationCase>> rules = flow.getNavigationCases();
         int rulesSize = rules.size();
 
         Map<String, Set<NavigationCase>> cases = new HashMap<String, Set<NavigationCase>>(
                 HashMapUtils.calcCapacity(rulesSize));
 
         List<_WildcardPattern> wildcardPatterns = new ArrayList<_WildcardPattern>();
 
         for (Map.Entry<String, Set<NavigationCase>> entry : rules.entrySet())
         {
             String fromViewId = entry.getKey();
 
             //specification 7.4.2 footnote 4 - missing fromViewId is allowed:
             if (fromViewId == null)
             {
                 fromViewId = ASTERISK;
             }
             else
             {
                 fromViewId = fromViewId.trim();
             }
 
             Set<NavigationCase> set = cases.get(fromViewId);
             if (set == null)
             {
                 set = new HashSet<NavigationCase>(entry.getValue());
                 cases.put(fromViewId, set);
                 if (fromViewId.endsWith(ASTERISK))
                 {
                     wildcardPatterns.add(new _WildcardPattern(fromViewId));
                 }
             }
             else
             {
                 set.addAll(entry.getValue());
             }
         }
 
         Collections.sort(wildcardPatterns, new KeyComparator());
 
         _flowNavigationStructureMap.put(
             flow.getId(), 
             new _FlowNavigationStructure(flow.getDefiningDocumentId(), flow.getId(), cases, wildcardPatterns) );
     }
     
     private synchronized void calculateNavigationCases(RuntimeConfig runtimeConfig)
     {
         if (_navigationCases == null || runtimeConfig.isNavigationRulesChanged())
         {
             Collection<? extends NavigationRule> rules = runtimeConfig.getNavigationRules();
             int rulesSize = rules.size();
 
             Map<String, Set<NavigationCase>> cases = new HashMap<String, Set<NavigationCase>>(
                     HashMapUtils.calcCapacity(rulesSize));
 
             List<_WildcardPattern> wildcardPatterns = new ArrayList<_WildcardPattern>();
 
             for (NavigationRule rule : rules)
             {
                 String fromViewId = rule.getFromViewId();
 
                 //specification 7.4.2 footnote 4 - missing fromViewId is allowed:
                 if (fromViewId == null)
                 {
                     fromViewId = ASTERISK;
                 }
                 else
                 {
                     fromViewId = fromViewId.trim();
                 }
 
                 Set<NavigationCase> set = cases.get(fromViewId);
                 if (set == null)
                 {
                     set = new HashSet<NavigationCase>(convertNavigationCasesToAPI(rule));
                     cases.put(fromViewId, set);
                     if (fromViewId.endsWith(ASTERISK))
                     {
                         wildcardPatterns.add(new _WildcardPattern(fromViewId));
                     }
                 }
                 else
                 {
                     set.addAll(convertNavigationCasesToAPI(rule));
                 }
             }
 
             Collections.sort(wildcardPatterns, new KeyComparator());
 
             synchronized (cases)
             {
                 // We do not really need this sychronization at all, but this
                 // gives us the peace of mind that some good optimizing compiler
                 // will not rearrange the execution of the assignment to an
                 // earlier time, before all init code completes
                 _navigationCases = cases;
                 _wildcardPatterns = wildcardPatterns;
 
                 runtimeConfig.setNavigationRulesChanged(false);
             }
         }
     }
 
     private static final class KeyComparator implements Comparator<_WildcardPattern>
     {
         public int compare(_WildcardPattern s1, _WildcardPattern s2)
         {
             return -s1.getPattern().compareTo(s2.getPattern());
         }
     }
     
     private Set<NavigationCase> convertNavigationCasesToAPI(NavigationRule rule)
     {
         Collection<? extends org.apache.myfaces.config.element.NavigationCase> configCases = rule.getNavigationCases();
         Set<NavigationCase> apiCases = new HashSet<NavigationCase>(configCases.size());
         
         for(org.apache.myfaces.config.element.NavigationCase configCase : configCases)
         {   
             if(configCase.getRedirect() != null)
             {
                 String includeViewParamsAttribute = configCase.getRedirect().getIncludeViewParams();
                 boolean includeViewParams = false; // default value is false
                 if (includeViewParamsAttribute != null)
                 {
                     includeViewParams = Boolean.valueOf(includeViewParamsAttribute);
                 }
                 apiCases.add(new NavigationCase(rule.getFromViewId(),configCase.getFromAction(),
                                                 configCase.getFromOutcome(),configCase.getIf(),configCase.getToViewId(),
                                                 configCase.getRedirect().getViewParams(),true,includeViewParams));
             }
             else
             {
                 apiCases.add(new NavigationCase(rule.getFromViewId(),configCase.getFromAction(),
                                                 configCase.getFromOutcome(),configCase.getIf(),
                                                 configCase.getToViewId(),null,false,false));
             }
         }
         
         return apiCases;
     }
     
     /**
      * A navigation command is an operation to do by the navigation handler like
      * do a redirect, execute a normal navigation or enter or exit a flow. 
      * 
      * To resolve a navigation command, it is necessary to get an snapshot of the
      * current "navigation context" and try to resolve the command.
      */
     protected static class NavigationContext
     {
         private NavigationCase navigationCase;
         private List<Flow> sourceFlows;
         private List<Flow> targetFlows;
         private List<FlowCallNode> targetFlowCallNodes;
         private List<Flow> currentFlows;
         private int returnCount = 0;
 
         public NavigationContext()
         {
         }
 
         public NavigationContext(NavigationCase navigationCase)
         {
             this.navigationCase = navigationCase;
         }
         
         public NavigationCase getNavigationCase()
         {
             return navigationCase;
         }
 
         public void setNavigationCase(NavigationCase navigationCase)
         {
             this.navigationCase = navigationCase;
         }
 
         public List<Flow> getSourceFlows()
         {
             return sourceFlows;
         }
 
         public List<Flow> getTargetFlows()
         {
             return targetFlows;
         }
         
         public List<FlowCallNode> getFlowCallNodes()
         {
             return targetFlowCallNodes;
         }
 
         public void addTargetFlow(Flow sourceFlow, Flow targetFlow, FlowCallNode flowCallNode)
         {
             if (targetFlows == null)
             {
                 sourceFlows = new ArrayList<Flow>(4);
                 targetFlows = new ArrayList<Flow>(4);
                 targetFlowCallNodes = new ArrayList<FlowCallNode>(4);
             }
             this.sourceFlows.add(sourceFlow);
             this.targetFlows.add(targetFlow);
             this.targetFlowCallNodes.add(flowCallNode);
         }
         
         public Flow getCurrentFlow(FacesContext facesContext)
         {
             if (currentFlows != null && !currentFlows.isEmpty())
             {
                 return currentFlows.get(currentFlows.size()-1);
             }
             else
             {
                 FlowHandler flowHandler = facesContext.getApplication().getFlowHandler();
                 return flowHandler.getCurrentFlow(facesContext);
             }
         }
         
         public void finish(FacesContext facesContext)
         {
             // Get back flowHandler to its original state
             for (int i=0; i < returnCount; i++)
             {
                 FlowHandler flowHandler = facesContext.getApplication().getFlowHandler();
                 flowHandler.popReturnMode(facesContext);
             }
             returnCount = 0;
         }
         
         public void popFlow(FacesContext facesContext)
         {
             if (currentFlows != null && !currentFlows.isEmpty())
             {
                 currentFlows.remove(currentFlows.size()-1);
             }
             else
             {
                 FlowHandler flowHandler = facesContext.getApplication().getFlowHandler();
                 flowHandler.pushReturnMode(facesContext);
                 returnCount++;
             }
         }
         
         public void pushFlow(FacesContext facesContext, Flow flow)
         {
             if (currentFlows == null)
             {
                 currentFlows = new ArrayList<Flow>();
             }
             currentFlows.add(flow);
         }
         
         public String getLastDisplayedViewId(FacesContext facesContext, Flow flow)
         {
             FlowHandler flowHandler = facesContext.getApplication().getFlowHandler();
             return flowHandler.getLastDisplayedViewId(facesContext);
         }
     }
 }